Ruler



FIG. 1 is a perspective view of a ruler showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof, the bottom plan view being identical thereto; and,

FIG. 5 is a right side elevational view thereof, the left side elevational view being identical thereto. 

The ornamental design for a ruler, substantially as shown and described. 